1/*
2 * Copyright (C) 2005 International Business Machines Corporation
3 * Copyright (c) 2005 by Trusted Computer Solutions, Inc.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the project nor the names of its contributors
15 *    may be used to endorse or promote products derived from this software
16 *    without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31
32#include "config.h"
33
34#include <sys/types.h>
35
36#include <stdlib.h>
37#include <stdio.h>
38#include <string.h>
39
40#include <selinux/selinux.h>
41#include <selinux/flask.h>
42#include <selinux/av_permissions.h>
43#include <selinux/avc.h>
44#include <selinux/context.h>
45
46#include "var.h"
47#include "vmbuf.h"
48#include "misc.h"
49#include "plog.h"
50
51#include "isakmp_var.h"
52#include "isakmp.h"
53#include "ipsec_doi.h"
54#include "policy.h"
55#include "proposal.h"
56#include "strnames.h"
57#include "handler.h"
58
59/*
60 * Get the security context information from SA.
61 */
62int
63get_security_context(sa, p)
64	vchar_t *sa;
65	struct policyindex *p;
66{
67	int len = 0;
68	int flag, type = 0;
69	u_int16_t lorv;
70	caddr_t bp;
71	vchar_t *pbuf = NULL;
72	vchar_t *tbuf = NULL;
73	struct isakmp_parse_t *pa;
74	struct isakmp_parse_t *ta;
75	struct isakmp_pl_p *prop;
76	struct isakmp_pl_t *trns;
77	struct isakmp_data *d;
78	struct ipsecdoi_sa_b *sab = (struct ipsecdoi_sa_b *)sa->v;
79
80	/* check SA payload size */
81	if (sa->l < sizeof(*sab)) {
82		plog(LLV_ERROR, LOCATION, NULL,
83			"Invalid SA length = %zu.\n", sa->l);
84		return -1;
85	}
86
87	bp = (caddr_t)(sab + 1); /* here bp points to first proposal payload */
88	len = sa->l - sizeof(*sab);
89
90	pbuf = isakmp_parsewoh(ISAKMP_NPTYPE_P, (struct isakmp_gen *)bp, len);
91	if (pbuf == NULL)
92		return -1;
93
94	pa = (struct isakmp_parse_t *)pbuf->v;
95        /* check the value of next payload */
96	if (pa->type != ISAKMP_NPTYPE_P) {
97		plog(LLV_ERROR, LOCATION, NULL,
98			"Invalid payload type=%u\n", pa->type);
99		vfree(pbuf);
100		return -1;
101	}
102
103	if (pa->len == 0) {
104		plog(LLV_ERROR, LOCATION, NULL,
105		"invalid proposal with length %d\n", pa->len);
106		vfree(pbuf);
107		return -1;
108	}
109
110	/* our first proposal */
111	prop = (struct isakmp_pl_p *)pa->ptr;
112
113	/* now get transform */
114	bp = (caddr_t)prop + sizeof(struct isakmp_pl_p) + prop->spi_size;
115	len = ntohs(prop->h.len) -
116		(sizeof(struct isakmp_pl_p) + prop->spi_size);
117	tbuf = isakmp_parsewoh(ISAKMP_NPTYPE_T, (struct isakmp_gen *)bp, len);
118	if (tbuf == NULL)
119		return -1;
120
121	ta = (struct isakmp_parse_t *)tbuf->v;
122	if (ta->type != ISAKMP_NPTYPE_T) {
123		plog(LLV_ERROR, LOCATION, NULL,
124		     "Invalid payload type=%u\n", ta->type);
125		return -1;
126	}
127
128	trns = (struct isakmp_pl_t *)ta->ptr;
129
130	len = ntohs(trns->h.len) - sizeof(struct isakmp_pl_t);
131	d = (struct isakmp_data *)((caddr_t)trns + sizeof(struct isakmp_pl_t));
132
133	while (len > 0) {
134		type = ntohs(d->type) & ~ISAKMP_GEN_MASK;
135		flag = ntohs(d->type) & ISAKMP_GEN_MASK;
136		lorv = ntohs(d->lorv);
137
138		if (type != IPSECDOI_ATTR_SECCTX) {
139			if (flag) {
140				len -= sizeof(*d);
141				d = (struct isakmp_data *)((char *)d
142				     + sizeof(*d));
143			} else {
144				len -= (sizeof(*d) + lorv);
145				d = (struct isakmp_data *)((caddr_t)d
146				     + sizeof(*d) + lorv);
147			}
148		} else {
149			flag = ntohs(d->type & ISAKMP_GEN_MASK);
150			if (flag) {
151				plog(LLV_ERROR, LOCATION, NULL,
152				     "SECCTX must be in TLV.\n");
153				return -1;
154			}
155			memcpy(&p->sec_ctx, d + 1, lorv);
156			p->sec_ctx.ctx_strlen = ntohs(p->sec_ctx.ctx_strlen);
157			return 0;
158		}
159	}
160	return 0;
161}
162
163void
164set_secctx_in_proposal(iph2, spidx)
165	struct ph2handle *iph2;
166	struct policyindex spidx;
167{
168	iph2->proposal->sctx.ctx_doi = spidx.sec_ctx.ctx_doi;
169	iph2->proposal->sctx.ctx_alg = spidx.sec_ctx.ctx_alg;
170	iph2->proposal->sctx.ctx_strlen = spidx.sec_ctx.ctx_strlen;
171		memcpy(iph2->proposal->sctx.ctx_str, spidx.sec_ctx.ctx_str,
172			spidx.sec_ctx.ctx_strlen);
173}
174
175
176/*
177 * function: 	init_avc
178 * description:	function performs the steps necessary to initialize the
179 *		userspace avc.
180 * input:	void
181 * return:	0	if avc was successfully initialized
182 * 		1	if the avc could not be initialized
183 */
184
185static int mls_ready = 0;
186
187void
188init_avc(void)
189{
190	if (!is_selinux_mls_enabled()) {
191		plog(LLV_ERROR, LOCATION, NULL, "racoon: MLS support is not"
192				" enabled.\n");
193		return;
194	}
195
196	if (avc_init("racoon", NULL, NULL, NULL, NULL) == 0)
197		mls_ready = 1;
198	else
199		plog(LLV_ERROR, LOCATION, NULL,
200		     "racoon: could not initialize avc.\n");
201}
202
203/*
204 * function: 	within_range
205 * description:	function determines if the specified sl is within the
206 * 		configured range for a policy rule.
207 * input:	security_context *sl		SL
208 * 		char *range		Range
209 * return:	1	if the sl is within the range
210 * 		0	if the sl is not within the range or an error
211 * 			occurred which prevented the determination
212 */
213
214int
215within_range(security_context_t sl, security_context_t range)
216{
217	int rtn = 1;
218	security_id_t slsid;
219	security_id_t rangesid;
220	struct av_decision avd;
221	security_class_t tclass;
222	access_vector_t av;
223
224	if (!*range)	/* This policy doesn't have security context */
225		return 1;
226
227	if (!mls_ready)  /* mls may not be enabled */
228		return 0;
229
230	/*
231	 * Get the sids for the sl and range contexts
232	 */
233	rtn = avc_context_to_sid(sl, &slsid);
234	if (rtn != 0) {
235		plog(LLV_ERROR, LOCATION, NULL,
236				"within_range: Unable to retrieve "
237				"sid for sl context (%s).\n", sl);
238		return 0;
239	}
240	rtn = avc_context_to_sid(range, &rangesid);
241	if (rtn != 0) {
242		plog(LLV_ERROR, LOCATION, NULL,
243				"within_range: Unable to retrieve "
244				"sid for range context (%s).\n", range);
245		sidput(slsid);
246		return 0;
247	}
248
249	/*
250	 * Straight up test between sl and range
251	 */
252	tclass = SECCLASS_ASSOCIATION;
253	av = ASSOCIATION__POLMATCH;
254	rtn = avc_has_perm(slsid, rangesid, tclass, av, NULL, &avd);
255	if (rtn != 0) {
256		plog(LLV_INFO, LOCATION, NULL,
257			"within_range: The sl is not within range\n");
258		sidput(slsid);
259		sidput(rangesid);
260		return 0;
261	}
262	plog(LLV_DEBUG, LOCATION, NULL,
263		"within_range: The sl (%s) is within range (%s)\n", sl, range);
264		return 1;
265}
266